Beginning Feb. 15, anyone coming to the United Kingdom from a country on its travel ban list of COVID-19 hotspots must quarantine in a government-approved hotel for 10 nights, the U.K. government announced Thursday.

Most foreign nationals from high-risk nations already face U.K. travel restrictions due to the coronavirus pandemic. But this new rule will apply to U.K. citizens and residents arriving from one of the 33 "red list" countries: Angola, Argentina, Bolivia, Botswana, Brazil, Burundi, Cape Verde, Chile, Colombia, Democratic Republic of the Congo, Ecuador, Eswatini, French Guiana, Guyana, Lesotho, Malawi, Mauritius, Mozambique, Namibia, Panama, Paraguay, Peru, Portugal (including Madeira and the Azores), Rwanda, Seychelles, South Africa, Suriname, Tanzania, United Arab Emirates, Uruguay, Venezuela, Zambia and Zimbabwe.

Security will escort guests to their quarantine rooms when they arrive and must accompany them if they wish to access outside space for fresh air or a smoke. Three meals per day and laundry service will also be provided during their stay.

Those in quarantine will be required to take a COVID-19 test on both Day 2 and Day 8.

ABC News’ Zoe Magee contributed to this report.

Denmark, the Netherlands and Norway have joined the growing list of European countries that have said they won't recommend older age groups receive the COVID-19 vaccine developed by England's University of Oxford and British-Swedish pharmaceutical giant AstraZeneca until more data from clinical trials becomes available.

The Danish Health Authority said Thursday that it will recommend the Oxford/AstraZeneca vaccine to people under the age of 65 who are not at risk of serious illness from COVID-19. The drugs regulator citied a lack of documentation as to the vaccine's efficacy in older age groups.

The Norwegian Institute of Public Health said it will also limit use of the Oxford/AstraZeneca vaccine to those under 65 because there had been few participants older than that in the trial conducted by AstraZeneca.

Meanwhile, the Dutch Health Council said the efficacy of the Oxford/AstraZeneca vaccine in those over 55 "cannot yet be calculated because they participated only to a limited extent in the vaccine studies."

Belgium, France and Germany have made similar moves recently, while Switzerland went a step further and declined to authorize the Oxford/AstraZeneca vaccine for any age group, citing insufficient data.

The number of COVID-19 vaccine doses delivered across the United States over the past week dropped 22.5%, but the amount of doses administered increased 13.5%, according to a report from the U.S. Department of Health and Human Services.

The country has also seen a three-week downward trend in new COVID-19 cases, resulting in a 44% decline in the seven-day daily average since the peak on Jan. 8, the report said.

Still, the current number of daily cases remains over twice as high as the numbers during prior peaks.

ABC News’ Brian Hartman and Josh Margolin contributed to this report.

There are currently 91,000 people hospitalized with COVID-19 in the United States -- the lowest since Nov. 28, which was two days after Thanksgiving, according to an ABC News analysis of data compiled by The COVID Tracking Project, a volunteer-run effort to track the U.S. outbreak.

COVID-19 hospitalizations have declined across the country by nearly 30% over the last three weeks.

In the span of three weeks, the national seven-day average of daily COVID-19 cases has declined by 45.6% -- the steepest and most consistent non-holiday-related drop in cases the U.S. has seen since the summer.

ABC News’ Arielle Mitropoulos contributed to this report.

There were 111,896 new cases of COVID-19 confirmed in the United States on Sunday, according to a real-time count kept by Johns Hopkins University.

Sunday's case count is the lowest the country has recorded since Dec. 25 and is also far less than the all-time high of 300,282 newly confirmed infections on Jan. 2, Johns Hopkins data shows.

An additional 1,794 fatalities from COVID-19 were registered nationwide on Sunday, down from a peak of 4,466 new deaths on Jan. 12, according to Johns Hopkins data.

COVID-19 data may be skewed due to possible lags in reporting over the Martin Luther King Jr. Day holiday weekend.

A total of 26,187,424 people in the U.S. have been diagnosed with COVID-19 since the pandemic began, and at least 441,331 have died, according to Johns Hopkins data. The cases include people from all 50 U.S. states, Washington, D.C., and other U.S. territories as well as repatriated citizens.

Much of the country was under lockdown by the end of March as the first wave of pandemic hit. By May 20, all U.S. states had begun lifting stay-at-home orders and other restrictions put in place to curb the spread of the novel coronavirus. The day-to-day increase in the country's cases then hovered around 20,000 for a couple of weeks before shooting back up over the summer.

The numbers lingered around 40,000 to 50,000 from mid-August through early October before surging again to record levels, crossing 100,000 for the first time on Nov. 4, then reaching 200,000 on Nov. 27 before topping 300,000 on Jan. 2.

So far, the U.S. Food and Drug Administration has authorized two COVID-19 vaccines for emergency use -- one developed by U.S. pharmaceutical giant Pfizer and its German partner BioNTech, and another developed by American biotechnology company Moderna and the National Institute of Allergy and Infectious Diseases. More than 32 million vaccine doses have been administered nationwide, according to the latest data from the Centers for Disease Control and Prevention.